Accuracy of the Pisiform Boost Test for the Diagnosis of Triangular Fibrocartilage Complex Tears in the Wrist-Pisiform Boost Test

Background: A retrospective study was conducted to evaluate the diagnostic accuracy of a novel examination technique, the 'Pisiform Boost Test,' in diagnosing a triangular fibrocartilage complex (TFCC) tear. Methods: Wrist arthroscopies performed between 2011-2021 were retrospectively reviewed. Patients' clinical records were evaluated to determine the result of the Pisiform Boost Test during clinical examination and TFCC tear within the body of the TFCC as seen at wrist arthroscopy. The Pisiform Boost Test is performed by first assessing for ulna fovea pain on passive ulna deviation of the wrist and then assessing pain while the clinician applies digital pressure over the pisiform and passive ulna deviation. Results: The pisiform Boost test was found to have a Sensitivity of 91% (95% CI, 81 - 97%) and a Specificity of 33% (95% CI, 14-59%) for the diagnosis of TFCC tears. Positive predictive value of 83%, a negative predictive value of 50%, and an accuracy of 78%. A chi-square test of independence was performed to examine the relation between a Positive Pisiform Boost Test and an arthroscopy-confirmed TFCC tear. The relation between these two variables was statistically significant, x2 (1, N = 82) = 6.4551, P=.011064. Conclusion: The Pisiform Boost Test demonstrates high sensitivity for TFCC tears (0.91). Specificity (0.33) is similar to that in the ulnar grinding test. Therefore, we propose this test be utilized with additional special tests for ulna-side wrist pain to allow clinicians to build a diagnostic picture, aiding decision-making and patient information.